#include<iostream>
#include<iomanip>
#include<cmath>
using ll=long long;
using namespace std;

bool check(ll a,ll b){
  if(a%b==0&&(a/b)%2==0)return true;
  return false;
}

int main(){
  ll x=343720,y=233333;
  ll t=1000;
  ll tx,ty;
  while(1){
    tx=t*15;
    ty=t*17;
    if(check(tx,x)&&check(ty,y))break;
    t++;
  }
  cout<<setprecision(2)<<fixed<<sqrt(tx*tx+ty*ty)<<endl;
  return 0;
}
